Part2 - How to revive / rejuvenate / fix rechargeable NiCd battery for cordless drill

** THIS WILL ONLY WORK FOR NICD BATTERIES - DO NOT DO IT TO NIMH OR LION **
This video will show you how to fix a bad or old NiCd battery for your cordless power tools. You need to have a power source that is double the voltage of your current battery. So if your battery is 18V, then you need a power source at 36V. You can use other cordless batteries and connect it in series.

The procedure is this:
1) let your bad battery drain to no voltage
2) connect the (-) lead of the 36V to the (-) lead of the 18V battery
3) quickly tap the (+) lead of the 36V to the (+) lead of the 18V battery, and repeat this quick tapping for 6-7 seconds, then STOP tapping it
4) you can use a multimeter to check the old battery and you should see a voltage of what that battery is rated for
5) now let the old battery sit for 15 minutes so the cells inside can cool down
6) put the old battery in the proper charger and let it charge fully
7) the battery should be as good as new
8) if it's not, you can repeat the above procedure couple more times

Category:

Howto & Style

Tags:

• fix
• revive
• rejuvenate
• recharge
• nicd
• failed
• dead
• cordless
• drill
• tool
• ryobi
• makita
• dewalt
• rigid
• black
• decker
• sears
• rechargeable
• charge
• power

[nicholasbiblelife]

thank you

[dial2fast]

@nicholasbiblelife You are welcome. Thank you for watching!

[Tiny960]

This is very helpful information. I tried on two (2) of my 18v Dewalt batteries and one worked out very well, but not the other. Every time, I tries rejuvenate, I would get very wildly spark and stick to terminal, but it not do to the other battery. Any advise from any one would be greatly apprecaite. My batteries is sbout 3.5 years old.

[dial2fast]

@Tiny960 If this method does not work for the other battery then there may be other issues with the cells which cannot be repaired. It may be time to toss it.

[BrabusTKR]

hey buddy, so does the source have to be Ni-Cd?????

[dial2fast]

@BrabusTKR Source does not have to be NiCd.

[hewie2k7]

hi, i have 2 dewalt 24v nicd's that dont fully hold a charge. will this method enable them to hold a full charge? and any sugestions what source to use ?

[lawrencejbaker2000]

I can't believe how simple this is. I wonder how many times you can do this on Nicad batteries.

[TheOcculus]

@TrydisMikee Look up Nickel Cadmium dendrite.

Lithium Ion and Nickel Metal Hydride batteries form dendrites too. Lead Acid battery dendrites are commonly called sulphation. I wouldn't recommend using this DIY technique on anything other than Ni-Cad.

There are high dollar industrial battery chargers for Hybrid transit coaches that incorporate high frequency voltage pulses an a "regeneration mode" to decrease or break up dendrite formation.

[hansonsux]

Also if you catch the crysal growth before the crystals get too big, you can reverse it by running the batteries through some charge/discharge cycles (how many depends on how big the cystals are).

[hansonsux]

Basically the crystals or dendrites grow to poke a hole in the separator, and short the cell to 0 volts. When you blow away the crystal, the damage to the separator is still there and so it creates the high self discharge. Also new dendrites will reform in short order so as soon as you leave the battery to discharge and it will short the cell again. Crystal growth can be caused by general neglect, such as leaving the batteries on continuous slow charge (overcharge).